Exam #3 Nutrition Flashcards
A secondary deficiency of a vitamin occurs when
absorption is inadequate or excessive amounts are excreted.
Secondary deficiency of a vitamin occurs when absorption is inadequate or excretion is excessive. Inadequate dietary intake of two or more vitamins causes multiple primary deficiencies. Dietary intake below physiologic needs is primary deficiency. Vitamin deficiency almost always occurs when an individual has protein-energy malnutrition.
An example of someone who has a relatively high risk for vitamin deficiencies is a(n)
elderly man living independently.
Subgroups of the population at risk for vitamin deficiencies include older adults because of decreased vitamin absorption and limited physical and economic resources to purchase and prepare food. Teenage athletes and college students usually consume enough food to ensure adequate vitamin intake. Vitamin deficiencies are rare among breastfed newborn infants.
Deficiencies are likely to develop most rapidly with low intakes of vitamin
C.
Vitamin C is water soluble; vitamins A, D, and E are fat soluble. Deficiencies of water-soluble vitamins develop more rapidly because they are not stored in the body.
The best way to ensure intake of a variety of phytochemicals is to
choose whole grains and include at least five servings of fruits and vegetables daily.
The best way to ensure intake of a variety of phytochemicals is to eat a variety of plant-based foods, including whole grains, fruits, and vegetables. Multivitamin supplements do not necessarily contain phytochemicals. Soy-based foods contain only a limited selection of phytochemicals. Dairy products do not contain phytochemicals; herbs and spices may provide some but are used in small quantities and so would not provide significant amounts.
The amount of thiamine that the body needs is related to
the amount of energy expended.
Thiamine needs are related to metabolic rate (i.e., energy expenditure) because thiamine is a coenzyme in energy metabolism. Thiamine is not directly involved in protein metabolism. The vitamin where requirements are inversely related to skin exposure to sunlight is vitamin D. Physiologic and emotional stress do not affect thiamine needs.
Deficiency of thiamine is characterized by
muscle weakness, loss of coordination, and tachycardia.
Symptoms of deficiency of thiamine include muscle weakness, loss of coordination, and tachycardia. Dermatitis, altered nerve function, and convulsions are symptoms of vitamin B6 deficiency. Skin rash, hair loss, loss of appetite, and depression are symptoms of biotin deficiency. Gingivitis, poor wound
The riboflavin in milk is protected by
using nontransparent containers.
Riboflavin is destroyed by ultraviolet light, so it is protected by use of nontransparent containers. Pasteurization destroys pathogenic bacteria. Homogenization prevents separation of milk and cream. Refrigerated storage increases the shelf life of milk.
The most significant source of riboflavin in the United States is
milk.
The most significant source of riboflavin in the United States is milk. Eggs, meats, and whole grains are all good but lesser sources of riboflavin.
Historically, deficiency of niacin was sometimes misdiagnosed as
mental illness.
Niacin deficiency was sometimes misdiagnosed as mental illness because of it causes symptoms of dementia. Alcoholism may contribute to niacin deficiency. Niacin deficiency is not generally related to viral infection or iron deficiency anemia.
Niacin can be manufactured by the body from the amino acid
tryptophan.
Niacin can be manufactured by the body from tryptophan, but not from alanine, arginine, or phenylalanine.
Pyridoxine functions in the body as a coenzyme in metabolism of
protein.
The active form of pyridoxine, pyridoxal phosphate, functions in the body as a coenzyme in the metabolism of protein and amino acids. It is not involved in metabolism of fat, protein, or energy.
A disorder in infants that is associated with inadequate intake of folate during pregnancy is
spina bifida.
Inadequate intake of folate during pregnancy is associated with spina bifida in infants. Cystic fibrosis and Down syndrome are genetic disorders. Macrocytic anemia is caused by an overt deficiency of folate, but is not usually found in infants in association with poor maternal intake during pregnancy.
Adequate intake of folic acid is especially important for
women of childbearing age.
Adequate intake of folic acid is especially important for women of childbearing age because adequate folate status during the first month of pregnancy helps prevent neural tube defects (spina bifida). Pregnant and lactating women have higher folic acid needs than nonpregnant women, but it is important to encourage adequate folic acid intake in all women of childbearing age because neural tube defects occur very early in pregnancy, before most women even realize they are pregnant. Competitive athletes, infants, and young children do not have special needs related to folic acid.
An example of a high-folate meal is
spinach salad with orange segments.
Good sources of folate include leafy green vegetables (including spinach), legumes, ready-to-eat cereals, and some fruits and juices (including orange). Fish, oatmeal, raisins, pork, and applesauce are not good sources of folate.
The type of anemia associated with folate deficiency is _____ anemia.
megaloblastic
The substance produced by the stomach that is necessary for absorption of cobalamin is
intrinsic factor.
The substance produced by the stomach that is necessary for absorption of cobalamin is intrinsic factor. Pernicious factor does not exist; pernicious anemia is caused by cobalamin deficiency. Hydrochloric acid is produced by the stomach, but is used to activate the enzyme pepsin (which helps digest proteins). Pyridoxal phosphate is the active form of pyridoxine or vitamin B6; it is not produced by the stomach or related to absorption of cobalamin.
Deficiency of vitamin B12 may cause damage to the
nerves.
Deficiency of vitamin B12 may cause damage to the brain, optic nerves, and peripheral nerves. Vitamin B12 deficiency is not associated with damage to the skin, eyes, or heart.
An example of a meal high in biotin is a
peanut butter and jelly sandwich.
The richest sources of biotin include liver, kidney, peanut butter, egg yolks, and yeast.
Pantothenic acid is required for
metabolism of carbohydrates, fats, and protein.
Pantothenic acid is part of coenzyme A, required for metabolism of carbohydrates, fats, and protein. It is not involved in absorption of amino acids, conduction of nerve impulses, or regulation of body temperature.
Some choline can be synthesized by the body from
methionine.
The body can synthesize some choline from methionine, but not enough to meet the needs of the body. The body cannot synthesize choline from glycerol, cholesterol, and tryptophan.
Vitamin C deficiency causes scurvy, which is characterized by
weakening of connective tissues.
Vitamin C deficiency causes breakdown of connective tissues. Diarrhea, dermatitis, and dementia are characteristic of niacin deficiency. Degeneration of nerves and muscles are not associated with deficiency of a specific vitamin. Vitamin C deficiency may be associated with iron deficiency anemia because vitamin C enhances absorption of nonheme iron. Vitamin C deficiency is not generally associated with weight loss.
Lifestyle behaviors that increase vitamin C requirements include
smoking cigarettes.
Smokers require more vitamin C than nonsmokers. Shift work, vegan diet, and fat intake do not affect vitamin C needs.
Vegetables are likely to be highest in vitamin C if they are
stir-fried.
Vegetables are likely to be highest in vitamin C if they are stir-fried. Heat destroys vitamin C, so cooking for the minimum amount of time preserves vitamin C. Vitamin C is water-soluble, so cooking methods that use water cause loss of vitamin C into the cooking liquid. Stir-frying cooks vegetables quickly without adding water. Boiling and canning both cause loss of vitamin C because of use of water. Oven roasting is a slow cooking method so more vitamin C is lost.
Vitamin A may be obtained by the body from precursors called
carotenoids.
The body can form vitamin A from carotenoids. Calciferols have vitamin D activity. Tocopherols have vitamin E activity. Rhodopsin is a substance formed from vitamin A in the retina.
An eye disorder associated with vitamin A deficiency is
xerophthalmia.
Vitamin A deficiency causes xerophthalmia. Myopia (near sight), retinopathy, and double vision are not related to vitamin deficiencies.
Vitamins that function as antioxidants in the body include
vitamins C and E.
The two vitamins that function as antioxidants in the body are vitamins C and E.
The Adequate Intake (AI) for vitamin D increases in older adults because
their skin is less efficient in synthesizing vitamin D during sun exposure.
Older adults need more dietary vitamin D because their skin is less efficient in synthesizing vitamin D during sun exposure. Their ability to absorb vitamin D and convert vitamin D to its active form has less effect of vitamin D needs. They do not necessarily require more total vitamin D than younger adults for bone health; they need more from foods because their skin manufactures less.
Symptoms of vitamin D toxicity include
high levels of calcium in the blood and urine.
Vitamin D toxicity causes high levels of calcium in the blood and urine because vitamin D enhances calcium absorption. Lethargy and loss of coordination indicates thiamine deficiency. Rickets, osteomalacia, and osteoporosis indicate vitamin D deficiency (not toxicity). Blistered skin, joint pain, and liver damage are signs of vitamin A toxicity.
Vitamin E requirements are related to intake of
polyunsaturated fats.
Vitamin E needs are related to intake of polyunsaturated fats because vitamin E prevents their oxidation. Vitamin E needs are not related to intakes of protein, vitamin C, and monounsaturated fats.
An example of a meal high in vitamin K is
stir fried beef with broccoli.
The best source of vitamin K is green leafy vegetables, such as broccoli. Dairy products, meats, cereals, and fruit provide smaller amounts.
Long-term antibiotic use may be associated with vitamin K deficiency because antibiotics
kill gut bacteria that synthesize vitamin K.
Antibiotics kill gut bacteria that synthesize vitamin K, so long-term use of antibiotics may cause vitamin K deficiency. Antibiotics do not interfere with vitamin K absorption, break down dietary vitamin K in the intestines, impair blood clotting, or increase vitamin K requirements.
The first step to ensuring adequate intake of vitamins is to
ensure that the diet includes a variety of foods from all of the food groups.
The best way to ensure adequate intake of vitamins is to start with a diet that includes a variety of foods from all the food groups. Reliance on supplements and food fortification do not result in an overall optimal diet. Use of supplements by specific subgroups of the population may be a second step in ensuring dietary adequacy, but would not be the first step.
Many Americans use vitamin supplements on a regular basis because
it is easier than making dietary and behavioral modifications.
It is often easier to take vitamin supplements than to make dietary and behavioral modifications to ensure that the diet provides adequate nutrients. Supplements do not taste good, and supplements are not necessary for good health for most people. Supplements are also not necessarily cheaper than foods containing a variety of nutrients.
If a woman who drinks a cup of decaffeinated coffee in the morning, a cup of fruit juice with lunch, 6 cups of water throughout the day and a cup of tea at bedtime, her fluid intake would be considered
optimal.
This woman’s total fluid intake for the day is 9 cups, the recommended amount for women. Minimum fluid intake for health is around 4 cups; intake below this would be considered dangerously low. Fluid intake can be too high, but the specific amount that causes water intoxication is unknown.
Hard water contains high levels of minerals such as
calcium and magnesium.
Hard water contains calcium and magnesium. Some natural water sources contain iron (this water may stain sinks and appliances brown). Lead is considered a contaminant in water. Softened water contains sodium. Zinc, sulfur, and potassium are not usually found in water.
Interstitial fluid is the body fluid
between the cells.
Interstitial fluid is the body fluid between the cells. The fluid within the cells is intracellular fluid; the fluid outside the cells is extracellular fluid; the fluid in the bloodstream is blood plasma.
Within the body, water helps to
regulate body temperature.
Within the body, water helps to regulate body temperature by absorbing and distributing heat throughout the body and via perspiration. Lipids do not dissolve in water. Water does not contain energy. Nerve fibers are insulated by myelin, not water.
Maintenance of physiologic equilibrium within the body is known as
homeostasis.
Maintenance of physiologic equilibrium within the body is known as homeostasis. Hemostasis is not a recognized term. Water balance is only one aspect of homeostasis. Metabolic regulation describes homeostasis, but is not the recognized term for it.
The hormone that causes the body to decrease sodium excretion is called
aldosterone.
The hormone that causes the body to decrease sodium excretion is aldosterone. Adrenaline is released in response to stress. Alanine is an amino acid, not a hormone. ADH causes the kidneys to decrease water excretion.
The primary intracellular electrolyte is
potassium.
The primary intracellular electrolyte is potassium. Sodium is the primary extracellular electrolyte. Calcium and magnesium are not electrolytes.
In an older adult who is usually very alert, disorientation may be a sign of
dehydration.
Disorientation may be a sign of dehydration, which is common in older adults, partly because their thirst mechanism is diminished. Iron deficiency anemia causes tiredness, but not disorientation. Severe malnutrition may affect mental acuity, but is less likely than dehydration. Edema causes swelling, but does not usually affect orientation.
Edema may be caused by inadequate intake of
protein.
Edema may be caused by inadequate intake of protein if protein levels in the body become so low that cellular fluid levels become imbalanced. Edema may be caused by high, not low, sodium levels and is not caused by low chloride or potassium levels.
The term bioavailability means the
amount of a mineral that can be absorbed by the body from a food.
Bioavailability is the amount of a mineral that can be absorbed by the body from a food. It is generally lower than the total amount of the mineral in a food. It may be related to the ratio of free to bound mineral in a food, but that is only one of many factors affecting bioavailability. It is not related to the amount excreted by the body.
Daily dietary calcium intake affects
bone calcium levels.
Long-term dietary calcium intake affects bone calcium levels. Calcium does not affect body temperature. The body maintains steady levels of calcium in the blood and muscles, using calcium from bone if dietary intake is insufficient.
Beverages that contain substances that decrease absorption of calcium include
tea.
Tea contains oxalic acid and tannins, both of which decrease absorption of calcium. Milk contains lactose and vitamin D which increase calcium absorption. Orange juice and bottled water do not have a significant positive or negative effect on calcium absorption.
Lifestyle changes that may help prevent development of osteoporosis include
taking a 30 minute walk most days.
Taking a 30 minute walk most days may help prevent development of osteoporosis because regular exercise stimulates an increase in bone density. Eating vegetable versus animal protein, increasing intake of fruit, and use of multivitamin supplements are unlikely to prevent osteoporosis (although they may have other health benefits).
An example of a food high in phosphorus is
cheese.
Foods high in phosphorus include dairy foods (such as cheese). Many processed convenience foods and soft drinks also contain phosphorus as additives. Fruits, vegetables, and rice are not good sources of phosphorus
A good source of calcium for someone who follows a strict vegetarian (vegan) diet would be
a bean burrito.
A good vegan source of calcium is a bean burrito because legumes contain calcium. Coconut milk and pasta salad are not good sources of calcium. Skim milk is not included in a vegan diet.
Magnesium deficiency may occur in association with
excessive vomiting and diarrhea.
Magnesium deficiency may occur secondary to excessive vomiting and diarrhea. Lactation, type 1 diabetes, and dehydration due to heat exposure do not cause magnesium deficiency.
Of the following, the food choice that contains the least sodium is
corn on the cob.
The food choice that contains the least sodium is corn on the cob. This is the least processed of all these forms of corn. Food processing usually involves addition of sodium.
